inline fan noise intake help

hi im in need of help i set my grow room up i have a dual cool tube running 2 4oo lights 1 mh and 1 hps
my 4 in inline fan is pulling cool air from outside works great to cool room and bring fresh air in
but i can hear it when i go outside any sugestions to help silence the noise btw i live in the friendly
medical marijuana state of colorado im a medical patient my neighbor knows i grow as this is my father in
laws house i just dont want anyone else to notice and try to bring the cops or break in

those things are known to be fucking noisy, that's for sure.. i had the same issues.. there's a few things that you can do to bring the noise down on them..
firstly, you can get a fan speed controller, and run the fan at like half speed, this step helps a lot as is... secondly, you can buy a duct muffler for the end of the duct work.. in combination with my fan speed controller, i'd say it brought the sound down by over 70% or so easily...
lastly, you can build a box around the fan to help with sound... there's a few good diy's on here showing you how to build one.. i think the name of the one thread was shhhh. quiet, the neighbors can hear you, the sound control thread...

hope that helps some m8...

I hung mine with bunji cords and cut over half the noise,I would not have beleived it but it sure as hell worked.Mine was extremly loud before we hung it..Ive seen the box work well also,theres threads on here for the build around box and bunji cords...

Mount it with rubber bushings if its the vibration you are hearing.

they do make silencers for these inline fans, maybe you could buy one, muffler or silencer its a big metal thing like a carbon filter, they also have sound proof ducting you could buy, although i dont think that will help with the noise outside
i have never tried myself

can you can hear the gush of air being sucked in /or is it the motor noise , how loud is the noise ? are you being a little bit over cautious, i only say this as 4 inch fans are normally very quiet ,
i have a 4 inch inline fan on my mother enclosure, i cant really hear it at all, i vent directly out of the enclosure into the main room as it only has cfls in it now
if the noise is high pitched and whiny i have found the larger fans can be quieter as the noise is deeper from say a 6inch than a 4inch
the turbo inline fans make more noise

hope that helps m8
skunkd0c

If you buy a speed controller buy a good one,the speedster allmost burnt my house down.Some mornings it just would not kick on,scapped it fast!!!

here's the link to the thread racerboy above mentions https://www.rollitup.org/indoor-growing/122532-quiet-neighbors-can-hear-you.html

@skunkdoc the noise i hear is air being pulled in its not loud but noticeable i guess it makes around the
same noise when the bathroom fan is on my wife says you cant notice it but i guess i notice it cause im looking for it
when i go outside

Please help! I am also in the same boat.

I bringing in air from outside through the window. With my 6in vortex. I have a phresh silencer connected to the intake side. (i decided this was the most effective spot) it is still extremely loud. i live in a populated area and cant have the noise rumbling about. there must be a way to fix this. any one? oh yeah its definitely the sound of the air being sucked into the fan not the noise of the fan motor itself.

It goes window ----> Phresh duct silencer--> Vortex ---> y spliter --> one directly into room the other into the 1000w hps.

one thing u guys have not done was dampen the vibations ....use rubber to connect it to holding /sitting places


one guy u need to buy a volt controll to allow u to turn down the fan so it not running on high all the time the sound will reduce some ........if u have to turn it so low that it is barely doing it job ......look at inline boosters...........they are only as loud as a fan on medium or a ac on low......i have 2 and i can sleep in the room they are in ....couch in there i pass out on sometimes

Timewalk said:

hi im in need of help i set my grow room up i have a dual cool tube running 2 4oo lights 1 mh and 1 hps
my 4 in inline fan is pulling cool air from outside works great to cool room and bring fresh air in
but i can hear it when i go outside any sugestions to help silence the noise btw i live in the friendly
medical marijuana state of colorado im a medical patient my neighbor knows i grow as this is my father in
laws house i just dont want anyone else to notice and try to bring the cops or break in

Click to expand...

Instead of using a inline fan for intake, try removing it and going passive.

DA BIG JIZZLE said:

Please help! I am also in the same boat.

I bringing in air from outside through the window. With my 6in vortex. I have a phresh silencer connected to the intake side. (i decided this was the most effective spot) it is still extremely loud. i live in a populated area and cant have the noise rumbling about. there must be a way to fix this. any one? oh yeah its definitely the sound of the air being sucked into the fan not the noise of the fan motor itself.

It goes window ----> Phresh duct silencer--> Vortex ---> y spliter --> one directly into room the other into the 1000w hps.

Click to expand...

The silencer must be located at least three feet from the outflow of the fan and not the other way around. I have an even better idea... Stop using forced air intake. There are a few reasons why you are supposed to use passive intake, one of them is because you stand the chance of creating a positive air pressure in the room which would leak odors out (when using forced air). The other reason is that there is no reason to not just cut 4x the amount of square inch area of your exhaust port(s) for your passive intake which would let the exhaust fan do all the pulling for you. It would be much quieter as well and you would save on electricity.P.S. don't believe everything you read in Jorge's "Grow Bible". I have a feeling that is where you got the idea to use forced air intake, although I could be wrong about that suspicion.

All fan manufactures always spec there fan installations to not be directly mounted to a structure because of sound ,vibrations . they recommend the use of a little something called a fan vibration isolator kit, and these kits are spec on the weight of the fan and or color coded for app. . this is the correct way of doing a fan installation , now lets move on to how close your fan is to the point of intake ,you can try moving your fan down to a father point from where the air enters , but I suspect that you have not properly sized your duct work and this is the main problem and any thing you due might help some ,but will not rid your problem completely. ,So with that being said if you do not use a proper fan isolation kit and use the proper size duct work you are wasting your time and some money.

contraptionated said:

The silencer must be located at least three feet from the outflow of the fan and not the other way around. I have an even better idea... Stop using forced air intake. There are a few reasons why you are supposed to use passive intake, one of them is because you stand the chance of creating a positive air pressure in the room which would leak odors out (when using forced air). The other reason is that there is no reason to not just cut 4x the amount of square inch area of your exhaust port(s) for your passive intake which would let the exhaust fan do all the pulling for you. It would be much quieter as well and you would save on electricity.P.S. don't believe everything you read in Jorge's "Grow Bible". I have a feeling that is where you got the idea to use forced air intake, although I could be wrong about that suspicion.

Click to expand...

@contraptionated - haha I did NOT get the forced intake idea from jorges grow bible. i got the idea from my friend due to lack of co2, we decided there was plenty of co2 on the busy street outside. and its much cooler outside than it is inside the garage. im not too worried about the odor, we smoke enough here anyways. haha. but what are you suggesting? that i pull the air across the light and out of the tent and exhaust out the window? or something?

@jrainman - it is not the vibration of the fan that is the problem but the sound of air wooshing into the ducting. i have the fan sitting on some type of foam and some bunched up towels so, vibrations are not a problem.

i swear i am close to finding an answer. check out the thread I opened for this question https://www.rollitup.org/indoor-growing/658621-need-quiet-intake-fan-noise.html#post9123342

From the audio perspective, please keep in mind that your level of ear sensitivity is higher than that of a passerby. There is a big psych difference between "what is there and making noise" for you and the actual noise level for somebody who happens upon the same area. You can get a leather cover. Hanging with bugee cords has worked best for me. Also the soft, spongey kitchen drawer lining can help with vibrations. I use that stuff a lot around the house.

No need to pass it through the light ( the intake air) . A cool tube will allow massive heat extraction but you will severely distort the color spectrum of the bulb ( whether or not the lens is made of Borosilicate glass as opposed to low iron glass). I did bring my intake air through the top of the sidewall where the wall meets the ceiling and I placed each exhaust port at the other end of the room so as to have all the air flowing through the upper portion of the room to extract more heat while at the same time allowing winter air to rush in from 0 degree temps outside without hurting anything. When the temp stabilizes the winter intake dampers shut and the warm weather intake dampers do their job when the thermostat signals ( the warm weather dampers allow intake air to flow in the conventional way from the bottom of a sidewall). That was how i used to do it and it worked great but the raised floor intake was the huge improvement.Now I just use the perforated raised floor as a diffuser to get maximum contact with the underside of the leaf and I place suction holes in the ceiling above each light fixture ( I do this in two rooms). There is a mechanical room between the two flowering rooms but located in the floor above the flowering rooms ( the mechanical room contains 3-10 can fans with can filter 150 and 8 foot long DIY duct silencer, this is the quasi lung room for both flowering rooms down in the basement and the air that gets sucked through the ceiling from each hole above each of the twelve 600 watt hps ( 6 per flowering room) goes to a seperate sealed room above each flowering room so as to eliminate the need for a 90 degree bend of duct so the air can go to the above and centrally located mechanical room ( the three fan/filter/silencer combos flip for each room) the warm air that travels through the sealed air handling room above each flowering room helps keep reserve water ( for weekly water changes) warm enough to use without using electric heaters. Let me not forget to mention that I still make air pass from the top of the sidewall on the direction blowing through my 6-400 watt metal halides of the veg room . The air that passes through the top of the veg room ( very unconventional to bring it in to the top and suck it out of the top) feeds the flowering rooms and eliminates the need for a ventilation system for the 2400 watts of veg. I literally get 3-10" can fan combos to do all the extraction for 4 rooms (2-3600 watt flowering rooms and 2-1200 watt veg rooms for 820 watts) about 150bucks a month of electricity for 9600 watts of light.

I'd say there a few solutions, first, buy two medium sized hooks and a bungie. Screw the hooks in and hang your fan from the bungies. Next, move it further away from the intake duct. Maybe think about placing it on the opposite side of the lights to where it is pulling in air, not pushing it. Also, they do make mufflers that work considerably well, from what I've been told. Hope this helps!